NEW GENERATION OF SOLAR COOLING AND HEATING SYSTEMS DRIVEN BY PHOTOVOLTAIC OR SOLAR THERMAL ENERGY An innovative HCP/T collector and its potential SHC applications Filippo Paredes Idea Srl fparedes@ideasrl.it
The mission Idea Srl is an integrator between research and industry, coordinating innovation projects in the fields of renewable energies and energy saving, low impact materials and products, environmental engineering, mechatronics.
MJ solar cells for HCPV Systems Why CPV? The most efficient solar cells are MJ cells based on III-IV compound semiconductor materials The higher efficiency cells used in CPV systems allows an higher energy density per square meter than traditional PV in locations with high DNI Graph of spectral irradiance Si solar cells Ga 0.35 In 0.65 P/Ga 0.83 In 0.17 As/Ge solar cells Source - N.V.Yastrebova (2007). High-efficiency multi-junction solar cells: current status and future potential
Solar cells for CPV Systems Why CPV? The new generations of multi-junction solar cells convert 46% of the solar light into electric power. Source: National Renewable Energy Laboratory (NREL) - National Renewable Energy Laboratory (NREL), Golden, CO United States Department of Energy
CPV Scenario The comparison at locations with high irradiation 2000KWh/m 2 a shows that PV have a lower reduction than CVP and CSP Actual limit of CPV : Greater investment costs than PV Complexity of the system Maintenance Reduced integration in urban area Development of a new generation of CHP module for competitive systems able to produce : Electrical energy Thermal Energy (for DHW and cooling) Desalination Light
IDEA UHCPV system primary and secondary optic Solar light is concentrated by double curvature parabolic mirrors 45x45 cm into a secondary optic. Solar beams are focused from an area of 0,2m 2 to 1cm 2 with a concentration factor of 2,000 suns. Optical losses in reflective and refractive transmissions are reduced using: - Solar glass with Ag reflective coating - Pure glass materials for secondary optic light pipe - High transmission glues for optical connection between components
UHCPV power generation HCPV system needs an active cooling circuit DNI : Concentrated solar power: 900 W/m2 160W Secondary optic Solar cells Module efficiency: 30% Electric energy: Available thermal energy: 50W e 110W th Concentrated solar radiation Max operative cell temperature 110 C
UHCPV - active cooling system Water inlet Water outlet DBC MJ Cell The MJ cell is connected to an active heat transfer system properly designed in order to reduce the thermal resistance of each substrate of connection material. The particular fluid dynamic geometry of the heat sink allows to keep the cell at a high level of electrical efficiency (ηel > 30%), while bringing the heat transfer fluid (water and glycol) up to an output temperature of 70-80 C, suitable for civil and industrial low temperature applications
HCE-PV/T system Idea HCPV system can act as a combined heat and power (CHP) solar system, generating both electricity from the photovoltaic (PV) cells and thermal energy (heat) (T) extracted from the cell s back surface. HCHE-PV/T (high concentration high efficiency thermo/photovoltaic system) shows a CHP efficiency of 72 to 85% with an electrical efficiency ranging from 27 to 30% and a thermal efficiency of about 45 to 55% within the temperature of 40-70 C of the cooling heat transfer fluid To be developed: an hybrid receiver reaching 90 C with an electric efficiency reduced by at most 2%
Tracking system and module configuration CPV MJ cells work with direct sun radiation North - South orientation 2 axis sun tracker is used for a module composed by 20 solar cells 20 primary and secondary optic Energy production 1 kw el peack 2 kw th peack Outlet water temperature 70 C S W E N
UHCPV modules and integration in urban areas The configuration of HCPV system can be integrated in urban areas for electrical and thermal energy use Net surface single mirror 2,025 cm2 Solar concentrator 2,000x Optical efficiency 90% N. Mirrors per module 20 n. Cells per module 20 Module Elect.efficiency 30% Module Thermal efficiency 45% Overall efficiency 75% Peak electrical power 1.000 W ep Peak thermal power 2.000 W thp Tracking system Dimension Weight Alt-Alt 1,4 x 6,5 m 280 Kg Heat transfer fluid glycol & water Flow rate per module 4 l/min Heating temperature 70 C
DNI [W/sqm] Power [W] HCPV power generation Example of energy produced: Solar field installed at the University Campus of Palermo 4 HCPV modules (80 MJ cells) HTF: desalinated water - Volume Storage 0.2m 3 Starting temperature 20 C T set point: 60 C DNI [W/mq] Electrical Power [W] Thermal Power [W] 1000 900 800 700 600 500 400 300 200 100 0 8500,00 7500,00 6500,00 5500,00 4500,00 3500,00 2500,00 Time [8th April 2017]
DNI [W/sqm] Energy [kwh] + Thermal efficiency [%] HCPV power generation Thermal efficiency: 45% Thermal energy gained in 5 operative hours: 35 kwh at 60 C Electric energy produced in 5 operative hours: 21 kwh DNI [W/mq] Thermal Energy [kwh] Thermal Efficiency [%] Electric energy [kwh] 1000 900 800 700 600 500 400 300 200 100 0 60 50 40 30 20 10 0
HCPV integrated for electricity and DHW demand Hydraulic and thermal layout for 5 HCPV modules for the roof of civil dwellings for DHW (and electricity) production
ZEB for heat and power generation H2020 Zero Plus Project Achieving near Zero and Positive Energy Settlement in Europe using Advanced Energy Technology 16% initial cost reduction with the reference case Net regulated energy consumption of less than 20 KWh/m 2 per year Energy production by RES of at least 50kWh/m2 per year HCPV installations: Voreppe (France) Paphos (Cyprus)
Thank you Filippo Paredes Idea Srl fparedes@ideasrl.it +39 3357680889